The present invention relates to heaters, and in particular to heat exchangers for fireplaces.
Fireplace heat exchangers are well known and widely used to improve the heating efficiency of conventional fireplace structures, such as those typically built in private, residential homes. Some of these devices comprise a plurality of heat transfer tubes which are interconnected in a side-by-side manner, and are generally C-shaped, with a base or grate portion adapted to retain burning wood or other fuels thereon, and an upper portion located in the firebox directly above the combustion area. The air in the room is circulated through the tubes by means of a blower or thermal siphoning. The tubes are heated by the fire, and transfer the absorbed heat to the air circulating through the tubes.
The heat transfer tubes commonly deteriorate rather quickly, because they are directly subjected to very high temperatures for extended periods of time. Since the tubes of many heat exchanger devices are welded together as a unit, when one of the tubes breaks through, the entire unit must be discarded and replaced. Although the heat transfer tubes of some fireplace heat exchangers can be individually replaced, they require a quite difficult and time consuming repair, because the various parts oxidize quickly and rust solidly together. Some of these devices provide a comparatively weak structure which is not capable of securely supporting the burning fuels thereon during extended use.
Further, heretofore fireplace heat exchangers did not usually include any means for humidifying the air which it heated, thereby detracting form the comfort of the room environment and requiring additional heat to achieve the same comfort level. Several attempts have been made to provide humidifiers for such units, however, none have proven both efficient and inexpensive.